The present disclosure relates to additive manufacturing systems for building three-dimensional (3D) parts with additive manufacturing techniques. In particular, the present disclosure relates to systems and processes for building 3D parts from powder-based additive manufacturing systems, and processes for removing unbound powder materials.
Additive manufacturing systems are used to build 3D parts from digital representations of the 3D parts (e.g., STL format files) using one or more additive manufacturing techniques. Examples of commercially available additive manufacturing techniques include fused deposition modeling, ink jetting, selective laser sintering, powder/binder jetting, electron-beam melting, and stereolithographic processes. For each of these techniques, the digital representation of the 3D part is initially sliced into multiple horizontal layers. For each sliced layer, a tool path is then generated, which provides instructions for the particular additive manufacturing system to form the given layer.
For example, a printer system that builds 3D parts with powder materials and binder resins typically deposits the powder materials in incremental layers. For each layer, the system also deposits (e.g., jets) a binder resin along tool paths pursuant to computer-generated instructions. The binder resin infiltrates the powder materials at the deposited locations, thereby binding the powder materials to form the given layer of the 3D part. This process may then be repeated for each successive layer until the 3D part is completed, where the unbound portions of the powder materials function as a support structure for the built layers of the 3D part.
Once the 3D part is built, the unbound powder materials are desirably removed. However, portions of the unbound powder materials may remain caked to the 3D part. The caked powder materials may be manually removed, such as by hand brushing. However, manual removal techniques are labor intensive and slow operations. Furthermore, purportedly-automated systems for removing powder materials typically require high shear air flows, which can blow the 3D part around within a chamber, thereby potentially damaging fine features of the 3D part.